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Re: VM/370 Hercules Optimisation
On Thu, 30 Jan 2020 at 15:57, Dave Wade <dave.g4ugm@...> wrote:
Was Adrian thinking that a page fault* would be the cause of the I/O?? Presumably if one accesses an address from within CMS that is not, at that moment, mapped to real memory it is CP, not CMS, that handles the page fault? * is there an IBM name for this as there seems to be for most other things.? |
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Re: VM/370 Hercules Optimisation
开云体育Joe, ? Not really much to do with IO. Hercules implements these as was mentioned earlier. Shadow Table Bypass is only relevant when running a guest OS that use virtual memory. CMS only runs with DAT off … ? Dave ? From: [email protected] <[email protected]> On Behalf Of Joe Monk
Sent: 30 January 2020 15:49 To: [email protected] Subject: Re: [h390-vm] VM/370 Hercules Optimisation ? So according to this guide there were VMASSISTS in ECPS:VM ?... ? ? Joe ? On Thu, Jan 30, 2020 at 9:37 AM adriansutherland67 <adrian@...> wrote:
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Re: VM/370 Hercules Optimisation
开云体育Adrian For CMS its pretty much the same!. That’s the who benefit of channels. You send the SIOs to the channel and the channel and controllers work out what to do. Dave ? From: [email protected] <[email protected]> On Behalf Of adriansutherland67
Sent: 30 January 2020 15:38 To: [email protected] Subject: Re: [h390-vm] VM/370 Hercules Optimisation ? On Thu, Jan 30, 2020 at 01:31 PM, Joe Monk wrote:
Cool - and in terms of CP (or VM/370) code is there much difference? |
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Re: VM/370 Hercules Optimisation
开云体育Back when I was in college, the administrative center was run on a 4341, and a 4331 was what supported all the campus’ student computing needs. ?I worked in the lab as an RJE operator.I think back then it was mostly DOS/VSE with POWER for the campus systems, and then later VM/360 with DOS/VSE running as a VM and eventually MUSIC as another VM for our first interactive computing for the students. ? I’m pretty sure the Admin 4341 was running MVS along with CICS. I liked MUSIC a lot, but the overall load was WAY more than the machine could handle and RJE job turnaround went up to 24 hours and beyond. ?I burned a lot of midnight oil keeping the printer fed so that the wait times didn’t just keep escalating. Whether that could be attributed to 43x1 channel performance would be interesting to discover. Fun times. Scott
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Re: VM/370 Hercules Optimisation
So according to this guide there were VMASSISTS in ECPS:VM ?... Joe On Thu, Jan 30, 2020 at 9:37 AM adriansutherland67 <adrian@...> wrote: On Thu, Jan 30, 2020 at 01:31 PM, Joe Monk wrote: |
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Re: VM/370 Hercules Optimisation
开云体育Joe, Interesting! Contrast that with the top of page 65:- ? GENERAL OPERATION OF THE CHANNELS The channels in the 4341 Processor are microcode and hardware controlled. They are integrated channels and, thus, share the use of certain hardware with the instruction processing function, such as the arithmetic logic unit, byte shifter, and control storage. ? The small 43xx were notorious for poor IO performance under heavy load reputedly because of this…. ? Dave ? From: [email protected] <[email protected]> On Behalf Of Joe Monk
Sent: 30 January 2020 12:02 To: [email protected] Subject: Re: [h390-vm] VM/370 Hercules Optimisation ? Dave, ? Huh? To quote the manual: ? "The 4341?Processor generates less?total?interference with instruction execution than intermediate-scale?System/360 and System/370?processors because the?amount?of time required?to transfer?a?byte?of?data?between?processor storage?and?the channel data buffer during?an?I/O operation?is?much?less?(64?bytes are transferred?in?4 microseconds?in the?4341 Processor?versus?4?bytes transferred to or?from?processor storage in?.54 microseconds?in the?Model 148,?for example)." ? I dont?see how that can degrade CPU performance for high I/O. In fact, in a high I/O situation, wouldnt?it help?? ? If 4 bytes are transferred in half a microsecond, that means 64 bytes could be transferred in 32 microseconds, versus 4 microseconds on a 4341... ? Joe ? On Thu, Jan 30, 2020 at 3:47 AM Dave Wade <dave.g4ugm@...> wrote:
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Re: VM/370 Hercules Optimisation
"I guess, in the context of hercules, we are looking for the device which required the fewest S/370 CPU cycles so that most of the work is done in?x86-64 land, but also one where the engineers didn't have to build in any weird waits or timing stuff into the CP drivers." If you look at the actual Hercules code, you can see that there is virtually no difference in how the various types of DASD are implemented... Joe On Thu, Jan 30, 2020 at 6:37 AM adriansutherland67 <adrian@...> wrote: On Thu, Jan 30, 2020 at 09:47 AM, Dave Wade wrote: |
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Re: VM/370 Hercules Optimisation
On Thu, Jan 30, 2020 at 09:47 AM, Dave Wade wrote:
On the low end 43xx boxes in effect the channel is implemented using some of the main CPU so device that generate high IO can degrade CPU performance…I guess, in the context of hercules, we are looking for the device which required the fewest S/370 CPU cycles so that most of the work is done in?x86-64 land, but also one where the engineers didn't have to build in any weird waits or timing stuff into the CP drivers. So it doesn't matter if the device was as slow as a dog in real life - as long as it delivers the requested block to the s/370 and VM/370 doesn't care if the interrupt (or whatever) happens VERY quickly. Also, perhaps there were some file system ASSISTS? Does that suggest anything to anyone? |
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Re: VM/370 Hercules Optimisation
Dave, The 2305 uses a block multiplexor channel ... "The 2835 storage Control and 2305 Fixed Head Storage Module form a large capacity, high -speed direct access storage facility for general purpose data storage and system residence.?It?attaches to the central processing unit through a block multiplexor channel, and operates under direct program control of the CPU." Joe On Thu, Jan 30, 2020 at 3:47 AM Dave Wade <dave.g4ugm@...> wrote:
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Re: VM/370 Hercules Optimisation
Dave, Huh? To quote the manual: "The 4341?Processor generates less?total?interference with instruction execution than intermediate-scale?System/360 and System/370?processors because the?amount?of time required?to transfer?a?byte?of?data?between?processor storage?and?the channel data buffer during?an?I/O operation?is?much?less?(64?bytes are transferred?in?4 microseconds?in the?4341 Processor?versus?4?bytes transferred to or?from?processor storage in?.54 microseconds?in the?Model 148,?for example)." If 4 bytes are transferred in half a microsecond, that means 64 bytes could be transferred in 32 microseconds, versus 4 microseconds on a 4341... Joe On Thu, Jan 30, 2020 at 3:47 AM Dave Wade <dave.g4ugm@...> wrote:
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Re: VM/370 Hercules Optimisation
开云体育Doug, On the low end 43xx boxes in effect the channel is implemented using some of the main CPU so device that generate high IO can degrade CPU performance… ? ? page 64. ? The channel throughputs are on 67. Your issue with the 2305 may have been that it needed a selector channel an whilst the machine can do that it reduces the number of block multiplexor channels… ? Dave ? From: [email protected] <[email protected]> On Behalf Of Doug Wegscheid
Sent: 30 January 2020 03:21 To: [email protected] Subject: Re: [h390-vm] VM/370 Hercules Optimisation ? 2305 was nice because of no seek time. In an Hercules emulated environment, probably doesn't make a difference. ? I was on the periphery of a 360/75 MVT -> 4341 MVT under VM transition (I got to do some MVT<->VM integration, much fun! HASP, CP SPOOL, VMCS....). 2305 was our MVT SYSRES. I heard that the channels on the 4341 couldn't keep up with the 2305, even if we dedicated it to the MVT virtual machine,and we had to drop back to a 3330 SYSRES. I'm not sure that last bit is accurate. ? The /75 sure was cool, though... ? On Wednesday, January 29, 2020, 2:48:12 PM EST, Drew Derbyshire <swhobbit@...> wrote: ? ? On 1/29/20 4:15 AM, adriansutherland67 wrote: |
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Re: CP Query
开云体育On 1/29/20 7:22 PM, Doug Wegscheid
wrote:
Have both.
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Re: VM/370 Hercules Optimisation
开云体育On 1/29/20 7:21 PM, Doug Wegscheid
wrote:
SSDs don't HAVE seek time, and for that matter modern I/O speed (even USB 2) versus 1970s parallel channel performance is no contest.?? But no one told VM all that, so it may still have the bias to emulated 2305s. For me, with real disk I/O to a USB 3 connected 500GB Samsung SSD on a 2 GB system with 1272 MB for buffer/cache, I/O is probably relatively speaking the one of fastest things on the system. -ahd- |
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Re: CP Query
I would ask why shouldn't X Y and Z report their own level, and not have to fold that into CP?
On Wednesday, January 29, 2020, 2:41:40 PM EST, Drew Derbyshire <swhobbit@...> wrote:
On 1/29/20 3:59 AM, Peter Coghlan wrote: > > However, I have to question if QUERY CPLEVEL is the right place to put this > information seeing as a Sixpack distribution is really composed of a certain > level of CP features, a certain level of CMS features and a bunch of compilers > and applications while QUERY CPLEVEL only describes one aspect of this. > Since the SixPakc include CP changes, it's definitively of? one the right places. Both CP and CMS should be report what their build level and their build date; so should the other components. Why would one omit the information from CP Q CPLEVEL just because it can't report X Y or Z which are not part of CP? |
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Re: VM/370 Hercules Optimisation
2305 was nice because of no seek time. In an Hercules emulated environment, probably doesn't make a difference. I was on the periphery of a 360/75 MVT -> 4341 MVT under VM transition (I got to do some MVT<->VM integration, much fun! HASP, CP SPOOL, VMCS....). 2305 was our MVT SYSRES. I heard that the channels on the 4341 couldn't keep up with the 2305, even if we dedicated it to the MVT virtual machine,and we had to drop back to a 3330 SYSRES. I'm not sure that last bit is accurate. The /75 sure was cool, though...
On Wednesday, January 29, 2020, 2:48:12 PM EST, Drew Derbyshire <swhobbit@...> wrote:
On 1/29/20 4:15 AM, adriansutherland67 wrote: > > For memory paging - I was wondering if IBM had a paging memory device > (clearly not - thanks). Therefore (1) I am going to go ahead with > experimenting with a small DASD drive for paging. I thought there was a bias towards 2305 devices for paging, but too much time hanging out with the documents for a certain 4361 and it's VM/SP flavor, my brain is probably fogged. -ahd- |
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Re: CP Query
开云体育Share file, didn’t want to undo existing stuff ? Dave ? From: [email protected] <[email protected]> On Behalf Of adriansutherland67
Sent: 29 January 2020 22:33 To: [email protected] Subject: Re: [h390-vm] CP Query ? On Wed, Jan 29, 2020 at 07:41 PM, Drew Derbyshire wrote:
Indeed, and I was just wondering how to report CMSLIB version, and of course GCC brexx etc all have versions. |
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Re: CP Query
On Wed, Jan 29, 2020 at 07:41 PM, Drew Derbyshire wrote:
Both CP and CMS should be report what their build level and their build dateIndeed, and I was just wondering how to report CMSLIB version, and of course GCC brexx etc all have versions. As for the distribution ... why not just have a version in a file on a shared drive and report it in a welcome message via a shared profile exec ... Something easy ... |
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Re: OK - So which version of Hercules ...
开云体育General Hercules discussions should be on the hercules-390 group… ? ? the history of how the forks occurred is complex and probably not worth discussing, what is important is where we are now. So 3.13 is in maintenance mode. Roger who wrote Hercules originally puts in what fixes he thinks are important. ? hercules-390/hyperion was meant to be v4.0 and to have a more accurate implementation of controllers and channels. I don’t believe a release has ever occurred, only snapshots. ? Hyperion is Fish’s fork of 4.0 …. ? … to quieten the console look at OSTAILOR ? ? Dave G4UGM ? From: [email protected] <[email protected]> On Behalf Of Steven Fosdick
Sent: 29 January 2020 19:49 To: [email protected] Subject: Re: [h390-vm] OK - So which version of Hercules ... ? On Wed, 29 Jan 2020 at 18:30, Peter Coghlan <groups@...> wrote:
? Does anyone know what the history is to what appear to be forks?? Is new development focused on Z/Architecture which is not very much interest if you are not intending to flout IBM's licensing terms, or are there things of interest for older OSes? ? I had a brief play with 4.2.1 SDL.? The first thing I noticed is that the Hercules console is somewhat noisier with messages that seem to be of more interest to someone developing Hercules than running it.? Does the logging system have a level of DEBUG that can have messages on for developers and off for users? ? Some option names in the config file have been changed in way that will, at least in the future, be incompatible.? That isn't a big deal in that I can soon clean up the config file but could have a bearing for things like the sixpack where a config file is shipped. ? The other, positive, thing I noticed is that the ECPS:VM has had more of the assists implemented and some documentation written for this feature.? Some of the documentation seems to apply to 3.13 too. ? I have GCC 9.2 and both 3.13 and 4.2.1 produce a barrage of compiler warnings.? Are any of the developers interested in checking these out to see if they represent bugs? ? I also believe there is a version that supports a fictitious 380 architecture which, if I remember what I read correctly, is happy to tell the OS that it uses 24 bit addressing and supports 16M of memory but allows programs that know better to get at the rest.
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Re: OK - So which version of Hercules ...
On 1/29/20 10:28 AM, Peter Coghlan wrote:
Spinhawk is also the version which Linux apt-get installs.? This is a major advantage, especially on funky platforms, made more so by the Hyperion build complexity.We have:My opinion is that of the choices given, 3.13 is the only one that has Give me a solid Hyperion build that the release apt-get package of which is kept updated on multiple Linux platforms (RPI, x64), and then we'll talk. |